Apparatus for overlapping sheets



April 3, 1965 M. SCHNEIDER 3,178,174

APPARATUS FOR OVERLAPPING SHEETS Filed May 16, 1962 4 Sheets-Sheet 1 A ril 13, 1965 M. SCHNEIDER 3,178,174

APPARATUS FOR OVERLAPPING SHEETS Filed May 16, 1962 4 Sheets-Sheet 2 April 3, 1965 M. SCHNEIDER 3,178,174

APPARATUS FOR OVERLAPPING SHEETS Filed May 16, 1962 4 Sheets-Sheet 3 April 13, 1965 M. SCHNEIDER APPARATUS FOR OVERLAPPING SHEETS 4 Sheets-Sheet 4 Filed May 16. 1962 United States Patent 3,178,174 APPARATUS FOR OVERLAPPING SHEETS Max Schneider, Dusseldorf, Germany, assignor to Jagenberg-Werke Akt.-Ges., Dusseldorf, Germany Filed May 16, 1962, Ser. No. 195,052 Claims priority, applicatiorbGennany, June 2, 1961,

0, 18 14 Claims. (Cl. 271-46) The invention relates to a method of and apparatus for conveying and depositing sheets moving from cross-cutters or other paper handling machines which sheets are over-lapped by effecting a braking effect and which sheets are moved further in the direction of travel at decreased speed and deposited.

In cross cutters or similar sheet dispensing machinery, there occurs generally behind the cross cutting means first a speed increase of the sheets in order to produce an interval between the individual sheets. This interval constitutes an essential requirement for a disturbance-free sliding of the sheets over each other during the formation of the over-lapping which is effected in a known manner by a retarding action which follows the previous speeding up of the sheets. In such situation, it is necessary for the purpose of initiating the overlapping to remove the rear edge of the preceding or leading sheet from the preceding or leading sheet from the range of movement of the front edge of the following sheet.

In the case of the cross cutters which operate at high speed, it is necessary to work with a substantial over-lapping which in turn makes necessary a substantial speed decrease of the sheets. Particularly in the case of thin papers, this speed decrease is of very great importance because it forms the basis for a slow and disturbance-free depositing of the sheets on the pile.

The speed decrease of the sheets occurs in such situation in a known manner in such a way that between the cross cutting means and the deposit pile, several conveyor means, preferably belt conveyors, are arranged in succession behind one another and in which each successive one operates at a slower speed than the preceding one. In this situation, the speed decrease can take place only step by step and gradually since a speed decrease which would be carried out over a short stretch or distance and suddenly would have the effect of stowing and wrinkling the sheets. The gradual speed decrease requires naturally expensive driving and conveying machinery and furthermore a relatively long conveyor path between the cross cutting means and the deposit pile or stack.

It is an object of the present invention to provide a conveyor apparatus between the cross cutting means and the deposit stack by means of which an effective disturbancefree and substantial ovcrlapping is assured within a short distance.

Starting from the known processes for conveying and depositing sheets moving from a cross cutting means which are overlapped by exerting a braking effect and are conveyed further at decreased speed and deposited, there is proposed, according to this invention, to pressure contact the rear edge or portion of the sheet, viewed in the direction of movement, in such a manner that it comes into the effective range of a braking means as well as being removed from the range of movement of the subsequent sheet. The pressure contact of the rearwardly positioned sheet end takes place in suchsituation at the upper side while the braking effect is effected at the under side. In carrying out this method, it is necessary to undertake the pressure contact of the sheet end, located rearwardly in the direction of movement, in a synchronous manner, namely, so as to be dependent on the advancing speed and/or the length of the sheet. In other words, the pressure contact and/or the braking of the rear end of the 3,178,174 Patented Apr. 13, 1965 "ice sheet take place in a manner which is dependent on the cutting sequence.

To carry out this method, means are employed which consists of an air jet component arranged in the area of the over-lapping zone above the conveyor path of the sheets and of an air suction component disposed below the conveyor path. The air jet component arranged above the conveyor path and adapted to effect pressure contact from above with the end of the sheet may be designed as a continuously rotating nozzle or as a stationary nozzle whose jet is controlled in synchronism with the operating cycle.

The control of the air jet in sequence with the working step may'be carried out in such situation photo-electrically or by means of a control component associated with the stationary nozzle which rotates and is provided with perforations on its perimeter.

The rotating control component is operatively connected with the cutting means and is formed by a jacket surrounding the nozzle with the periphery of the jacket being provided with perforations. The perforations extend over the entire width of the jacket and are distributed uniformly over the periphery in such a manner that in the case of a corresponding speed of rotation of the jacket which is driven by the cutting means, the release of the air jet through the perforations occurs in synchronism with the cutting speed of the cutting means. In this case, the perforationsmay be formed by rows of openings and/ or slots which extend axially.

The nozzle and the jacket are adjustable relative to each other around their common axis so that the angle at which the air jet strikes the sheet is adjustable. Furthermore, the arrangement is so designed that the jacket which is driven by the cutting means and which rotates in synchronism therewith is adjustable relative to the cutting means.

A further object of the invention for making pressure contact with the rear end of the sheet is provided by mechanical means. In this case, a rotating or oscillating press-down component is provided in the area of the overlapping area which carries the end of the sheet into the operating zone of the braking means and simultaneously out of the range of movement of the subsequent sheet.

For the braking effect of the end of the rear sheet at its undersurface, a suction means may be arranged in the conveyor plane which is provided with a stationary, a rotary, or a reciprocating suction surface. Furthermore, mechanical braking members may be employed for braking the rear end of the sheet at the undersurface of the sheet with these braking members having stationary, rotary or reciprocating surfaces, in which case it is advisable that the effective surfaces of these braking members have an increased friction resistance.

Further objects and advantages of the invention will become more readily apparent from the following detailed description and attached drawings, and in which drawings:

FIG. 1 is a diagrammatic illustration of the cross cutterwith the conveyor apparatus and the overlapping station and the depositing stack.

FIGS. 2, 3 and 4, respectively, show the overlapping and braking station with the air blower and braking memher in different operation phases;

FIGS. 5, 6 and 7, respectively, show another embodiment of the overlapping and braking station with mechanical pressure contact and braking of the sheet in different operation phases;

FIG. 8 shows an embodiment fora photoelectric control of the air pressure component;

FIG. 9 shows diagrammatically a cross cutter including a rotating control component for the compressed air; and

PEG. 10 shows the rotating control component on an enlarged scale.

As best shown in FIG. 1, a paper web 1 coming from a roller system (not illustrated) is conducted by means of advancing rollers 2 to a cross cutting means 3 and divided by such means into individual sheets 4. The sheets 4 which leave the cross cutting means 3 are first gripped by a first conveyor means which consists of rapidly traveling upper conveyor belts 5 and rapidly traveling lower conveyor belts 6. The conveyor belts 5 and 6 have a speed which is somewhat greater than the speed of the paper web 1 whereby an interval is produced between the individual sheets, which is favorable for the overlapping. During the further course, the sheets 4 travel over a ransfer table 7 and over a guide roller 8 to an overlapping and braking station which is arranged in the area of a slowly traveling lower conveyor belts 9. The sheets 4 which are now conducted by the conveyor belts 9 in an overlapped condition are gripped upon further forward movement by ejecting or removing belts 10 and by ejecting roller 11 and are deposited on stack 12.

The construction, arrangement and operation of tie overlapping and braking station is best illustrated in FIGS. 2, 3 and 4. Above the travel path of the sheets 4, is arranged a compressed air component in the form of a rotating compressed air nozzle 13 which is driven by the rotating cross cutting means 3 by means (not shown), and in such fashion as to be dependent on the cross cutting means. The air nozzle 13 is surrounded by a stationary jacket or shield 14 which is provided with an opening 15 which opens in the direction of the travel path of the sheets Below the travel path of the sheets 4 is located an air suction member defined by a suction box 16 whose upper end is covered by the conveyor belt 5 which is perforated or is made of a porous material. Freely rotatable rollers 17 in the box support the conveyor belt 9 and reduce the friction. Between the guide roller 8 and the conveyor belt 9 is disposed a plate 18 whose effective surface is located in the plane of the conveyor belt while the effective surface of the conveyor belt 9 is located in a plane lying somewhat lower. The suction box in may also be so formed that it is connected as an independent braking member forming a portion of the conveyor track between the plate 13 and the conveyor belt 9 wherein its effective upper surface is either stationary or is made as a suction valve which is driven in the same or in the opposite direction.

The operation of the overlapping and braking device is as follows:

The sheet 4 which is conducted by the conveyor belts 5 and 6 at high speed passes over plate 18 into the enlarged intermediate space between the conveyor belts 5 and 9 and is lowered clue to the air cushion present, only relatively slowly upon the conveyor belt 9 or on the preceding sheet 4. When the edge of the sheet, which lies in the rear as viewed in the direction of movement, is located in the area of plate 18, as may be seen in FIG. 2, the rotating compressed air nozzle 13 comes into the range of op ning 15 of the jacket 14 and air is directed against the rear end of the sheet with the effect that the underside of the rear end of the sheet is pressed against the upper end of the suction box 16 where the full braking force becomes eifective so that the slow speed of the conveyor belt 9 is imparted to the sheet.

The essential advantage or this operation lies in imparting a braking effect upon the rearwardly placed sheet end (viewed in the direction of the movement), whereby the speed of the sheet is substantially reduced while it is stretched out and the rear edge of the sheet is furthermore forcibly removed from the area of movement of the following sheet.

In the case of the embodiment illustrated in FIGS. 5, 6 and 7, there is provided in lieu of the rotating compressed air jet nozzle 13, a press-down component 19 which is also driven by the rotating cross cutting means 3,

which member 19 is pressed or forced in the synchronism of the operating cycle upon the upper side of the rearward end of the sheet.

In a further modification of the embodiment shown in FIGS. 1-4, there is provided in FIGS. 5, 6 and 7 a mechanical braking component which includes several brake bands 20. These brake bands 25) are arranged between the conveyor belt 9 in such a manner that the effective surfaces of the brake bands 20 are located somewhat higher than the effective surfaces of the conveyor belt 9. Depending on the existing operating conditions and the desired braking effect, the bands 2i may be driven so as to run in the same direction or so as to run in the opposite direction, or they may be arranged in a stationary manner. By a corresponding selection of the material or by a corresponding treatment of the surface of bands 20, an increased friction resistance may be provided. Otherwise, the operation of these mechanical embodiments corresponds to the o eration of the arrangement described with reference to FIGS. 1-4.

A further arrangement is illustrated in FIG. 8. In this embodiment, there is arranged in the area of the overlapping station or zone, a stationary compressed air nozzle 21 which is connected by a conduit 22 with a compressed air source or generator (not shown). In the conduit 22, a magnetic valve 23 is connected which valve is actuated via an amplifier 24 by the impulse of a photocell 25. The photocell 25 is arranged above the conveyor path of the sheets, and viewed in the direction of movement, in front of the overlapping station and the cell senses the sheet ends or the intervals or gaps between the individual sheets. This sensing involves releasing via amplifier 24 and the magnetic valve 23 a short compressed air jet through nozzle 21 whereby, as already mentioned, the rear end of sheet 4 is pressed or forced against the suction box 16. Suction box 16 may also be replaced by some other suitable mechanical braking member. Dependent on the interval between the photocell 25 and the nozzle 21, it may be necessary to connect a storage or retarding means for the starting impulse in the control circuit in order to determine exactly when the compressed air jet becomes effective in point of time.

In the embodiment shown in FIGS. 9 and 10, the compressed air component includes a stationary compressed air nozzle 26 and a rotating jacket or shield 27, which jacket is provided with perforations 28. Below the conveyor path of sheets 4 in the area of the compressed air component 26, there is located as in the previously described embodiments, a braking component. By way of a bevel gear drive 29, the jacket 27 is connected in an operative manner with the cutting means 3, so that the jacket is driven depending on the cutting sequence of the cutting means 3. A relative displacement of the jacket 27 with respect to the cutting means 3 makes possible the adjustment of the compressed air jet in relation to the sheet length. Furthermore, the compressed air nozzle 2:? is arranged adjustably for the purpose of changing the angle at which the air jet strikes the sheet 4.

The air for the suction box 16 is controlled also by means (not shown) dependent on the cutting means 3 whereby there is provided an arrangement which ensures only the rear end of the sheet is braked by the suction air.

The invention is not to be confined to any strict conformity to the showings in the drawings, but changes or modifications may be made therein, so long as such changes or modifications mark no material departure from the spirit and scope of the appended claims.

I claim:

1. An apparatus for handling paper comprising means for cutting a paper web into individual sheets, conveyor means for moving the sheets from the cutting means along a predetermined path of travel at such a speed as to provide a clearance between the rear edge of a leading sheet and the front edge of a following sheet, means for overlapping the sheets arrange in the path of travel of the.

air 8,174

sheets, said overlapping means including conveying means travelling at a slower speed than the conveyor means and having an entrance end and an exit end, means below the conveying means adjacent the entrance end thereof cooperable with the lower surface of a sheet for attaching the sheet to the conveying means thereby applying a braking action to the sheet, pressure contact means located above the conveying means and in proximity to the means for attaching the sheet to the conveying means for deflecting the rear edge of the sheet into contact with the conveying means for movement therewith and for removing the rear edge of such sheet from the area of movement of the front edge of a following sheet, and means for depositing the overlapped sheets leaving the exit end of said conveying means.

2. The apparatus as claimed in claim 1 in said pressure contact means includes a press down component controlled in synchronism with the operating cycle.

3. The apparatus as claimed in claim 1 in which said attaching means includes braking surfaces movable relatively to said conveying means and including a portion located above said conveying means.

4. The apparatus as claimed in claim 1 in which said attaching means includes a stationary braking surface having a portion located above the conveying means.

5. The apparatus as claimed in claim 3, in which the braking surfaces are provided with increased friction resistance.

6. An apparatus for handling paper comprising means for cutting a paper web into individual sheets, conveyor means for moving the sheets from the cutting means along a predetermined path of travel at such a speed as to provide a clearance between the rear edge of a leading sheet and the front edge of a following sheet, means for overlapping the sheets arranged in the path of travel of the sheets, said overlapping means including conveying means travelling at a slower speed than the conveyor means, a suction box below the conveying means for applying a braking action to the lower surface of a sheet on the conveying means, a nozzle adapted to direct a compressed air jet located above the conveying means and suction box for bringing the rear edge of a sheet into the effective range of the suction box and for removing the rear edge of such sheet from the area of movement of the front edge of the following sheet, and means for depositing the overlapped sheets leaving said overlapping means.

7. The apparatus as claimed in claim 6, including means continuously rotating said nozzle with the jet operation being limited to the area of the rear edge of the sheet.

8. The apparatus as claimed in claim 6, in which said nozzle is stationary and means being provided for controlling the air jet in synchronism with the operating cycle.

9. The apparatus as claimed in claim 6, in which said nozzle is stationary and a rotatable control means provided with apertures associated with said nozzle.

10. The apparatus as clmmed in claim 9, including means operably connecting the rotatable control means with the cutting means.

11. The apparatus as claimed in claim 9, in which said control means is defined by a jacket surrounding said nozzle.

12. The apparatus as claimed in claim 11 in which said apertures are located uniformly about the perimeter of and extend over the width of said jacket.

13. The apparatus as claimed in claim 12 in which said apertures are defined by rows of openings extending in the axial direction.

14. An apparatus for handling paper comprising means for cutting a paper web into individual sheets, conveyor means for moving the sheets from the cutting means along a predetermined path of travel at such a speed as to pro vide a clearance between the rear edge of a leading sheet and the front edge of a following sheet, means for overlapping the sheets arranged in the path of travel of the sheets, said overlapping means including conveying means travelling at a slower speed than the conveyor means, a suction box provided with a suction surface having movement relative thereto below the conveying means for applying a braking action to the lower surface of a sheet on the conveying means, pressure contact means located above the conveying means and suction box for bringing the rear edge of such sheet into the effective range of the suction box and for removing the rear edge of such sheet from the area of movement of the front edge of the following sheet, and means for depositing the overlapped sheets leaving said overlapping means.

References Cited by the Examiner UNITED STATES PATENTS 2,177,460 10/39 Renz 271--76 2,261,972 11/41 Matthews 271-74- 2,919,789 1/60 Coakley 27146 X ROBERT B. REEVES, Acting Primary Examiner.

EUGENE R. CAPOZIO, ROBERT B. REEVES,

Examiners, 

1. AN APPARATUS FOR HANDLING PAPER COMPRISING MEANS FOR CUTTING A PAPER WEB INTO INDIVIDUAL SHEETS, CONVEYOR MEANS FOR MOVING THE SHEETS FROM THE CUTTING MEANS ALONG A PREDETERMINED PATH OF TRAVEL AT SUCH A SPEED AS TO PROVIDE A CLEARANCE BETWEEN THE REAR EDGE OF A LEADING SHEET AND THE FRONT EDGE OF A FOLLOWING SHEET, MEANS FOR OVERLAPPING THE SHEETS ARRANGED IN THE PATH OF TRAVEL OF THE SHEETS, SAID OVERLAPPING MEANS INCLUDING CONVEYING MEANS TRAVELLING AT A SLOWER SPEED THAN THE CONVEYOR MEANS AND HAVING AN ENTRANCE END AND AN EXIT END, MEANS BELOW THE CONVEYING MEANS ADJACENT THE ENTRACE END THEREOF COOPERABLE WITH THE LOWER SURFACE OF A SHEET FOR ATTACHING THE SHEET TO THE CONVEYING MEANS THEREBY APPLYING A BRAKING ACTION TO THE SHEET, PRESSURE CONTACT MEANS LOCATED ABOVE THE CONVEYING MEANS AND IN PROXIMITY TO THE MEANS FOR ATTACHING THE SHEET TO THE CONVEYING MEANS FOR DEFLECTING THE REAR EDGE OF THE SHEET INTO CONTACT WITH THE CONVEYING MEANS FOR MOVEMENT THEREWITH AND FOR REMOVING THE REAR EDGE OF SUCH FROM THE AREA OF MOVEMENT OF THE FRONT EDGE OF A FOLLOWING SHEET, AND MEANS FOR DEPOSITING THE OVERLAPPED SHEETS HAVING THE EXIT END OF SAID COVEYING MEANS. 